Dalida was born in Egypt, but spent most of her career in France. She spoke French, Italian, Spanish, German, Arabic. She performed and recorded in 11 languages (French, Italian, German, Spanish, English, Egyptian and Levantine Arabic, Japanese, Hebrew, Dutch and Greek).

Tarja Turunen: she speaks Finnish, Spanish and English. She has recorded/sung songs in English, Finnish, Spanish, Italian, German, French, Swedish and Latin. The song "Mystique Voyage" is sung in Spanish, English and Finnish.

I found that Melody speaks English and French, and Elisa Italian and English... I believe if I include artists that speak two languages, that the list will be too long. So for now I'm adding only artists that speak more than two. I added Mina, L'Aura and Anita. Thank you!

I added Raffaella, however, I found that Enya speaks (only) two of those languages fluently, English and Irish Gaelic. I believe if I include artists that speak two languages, the list will be too long... So for now I'm adding only artists that speak more than two. Thank you!

I had been busy so it took me a while to add these...sorry for that. Thank you! I'll have to ask though...
Can you tell me does Tiziano speak French and Portuguese or has just recorded songs in those languages?
And does Yasmin speak Catalan? I found that she only sings in Ladino, but doesn't speak it, for example. I can't seem to find that info...

As far as I know, Cliff Richard doesn't actually speak German, even though he recorded some hit songs in German. I vaguely remember an interview on German television during which he said that all the lyrics were spelled out phonetically for him during recording sessions and that he didn't actually understand a word of what he was singing.

According to their website, the wonderful Mediæval Bæbes sing in "in an impressive array of obscure and ancient languages".https://lyricstranslate.com/en/mediaeval-baebes-lyrics.html
I'm not sure how many different languages exactly but am sure Wikipedia can answer that question. However, I very much doubt that they actually speak these languages, so if this is a condition, they are disqualified.

According to Wiki: They sing in a variety of languages, including Latin, Middle English, French, Italian, Russian, Swedish, Scottish English, German, Manx Gaelic, Spanish, Welsh, Bavarian, Provençal, Irish, modern English and Cornish. Impressive, indeed. I'm not finding though how many languages they, or at least one of them, actually speaks.

Pink Martini are a successful band who jump between many languages on their albums.https://lyricstranslate.com/en/pink-martini-lyrics.html
China Forbes (their main vocalist) sings in 15 languages, but she is monolingual and learns the songs phonetically, so I guess she doesn't qualify.

You should remove Croatian or Serbian from the lists and include just one (the main one fot the person) because they are like 90% same and if you speak one you can speak the other, or add both to all singers that speaks one of them. Serbo-Croatian is a good compromise.

I had added Croatian by mistake, somehow I was sure that he had some songs in Croatian standard. I disagree that if you can speak one you can speak the other... you can mainly understand the other, but I consider it an urban myth that you can speak the other automatically. There are many differences that even the natives aren't fully aware of. But I wouldn't want to turn this into that kind of discussion... Thank you, I corrected it.

Hi! Very fitting collection for this page
Perhaps Eivør (Pálsdóttir) would be a good artist to add as she has sung in Faroese (Native), English, Danish, Icelandic and Swedish. Of which it is likely that she speaks all of these languages. https://lyricstranslate.com/en/eivor-palsdottir-lyrics.html

The greek singer Νάνα Μούσχουρη (Nana Mouskouri).
During the span of her music
career she has released over 200 albums and singles in 10 different languages, including Greek, French, English, German, Dutch, Italian, Portuguese, Spanish,
Hebrew, Welsh, Mandarin Chinese and Corsican.

Naviband speak Belarusian, Russian and English, and have songs in Belarusian and Russian.
Irina Bilyk speaks Ukrainian, Polish, and Russian (I'm not sure if she speaks English) and has songs in all the three languages above.
Tina Karol speaks Ukrainian, Russian, and English, and has songs in all of them too.
O. Torvald speak Ukrainian, Russian, and English, though the frontman admits he is reluctant to speak Russian, according to Wikipedia.
There are many artists from Ukraine who can speak Ukrainian, Russian, and English. Are you going to list all of them?